moduleparam.h 8.7 KB

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  1. #ifndef _LINUX_MODULE_PARAMS_H
  2. #define _LINUX_MODULE_PARAMS_H
  3. /* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */
  4. #include <linux/init.h>
  5. #include <linux/stringify.h>
  6. #include <linux/kernel.h>
  7. /* You can override this manually, but generally this should match the
  8. module name. */
  9. #ifdef MODULE
  10. #define MODULE_PARAM_PREFIX /* empty */
  11. #else
  12. #define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
  13. #endif
  14. /* Chosen so that structs with an unsigned long line up. */
  15. #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
  16. #ifdef MODULE
  17. #define ___module_cat(a,b) __mod_ ## a ## b
  18. #define __module_cat(a,b) ___module_cat(a,b)
  19. #define __MODULE_INFO(tag, name, info) \
  20. static const char __module_cat(name,__LINE__)[] \
  21. __used \
  22. __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
  23. #else /* !MODULE */
  24. #define __MODULE_INFO(tag, name, info)
  25. #endif
  26. #define __MODULE_PARM_TYPE(name, _type) \
  27. __MODULE_INFO(parmtype, name##type, #name ":" _type)
  28. struct kernel_param;
  29. /* Returns 0, or -errno. arg is in kp->arg. */
  30. typedef int (*param_set_fn)(const char *val, struct kernel_param *kp);
  31. /* Returns length written or -errno. Buffer is 4k (ie. be short!) */
  32. typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp);
  33. struct kernel_param {
  34. const char *name;
  35. unsigned int perm;
  36. param_set_fn set;
  37. param_get_fn get;
  38. union {
  39. void *arg;
  40. const struct kparam_string *str;
  41. const struct kparam_array *arr;
  42. };
  43. };
  44. /* Special one for strings we want to copy into */
  45. struct kparam_string {
  46. unsigned int maxlen;
  47. char *string;
  48. };
  49. /* Special one for arrays */
  50. struct kparam_array
  51. {
  52. unsigned int max;
  53. unsigned int *num;
  54. param_set_fn set;
  55. param_get_fn get;
  56. unsigned int elemsize;
  57. void *elem;
  58. };
  59. /* On alpha, ia64 and ppc64 relocations to global data cannot go into
  60. read-only sections (which is part of respective UNIX ABI on these
  61. platforms). So 'const' makes no sense and even causes compile failures
  62. with some compilers. */
  63. #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
  64. #define __moduleparam_const
  65. #else
  66. #define __moduleparam_const const
  67. #endif
  68. /* This is the fundamental function for registering boot/module
  69. parameters. perm sets the visibility in sysfs: 000 means it's
  70. not there, read bits mean it's readable, write bits mean it's
  71. writable. */
  72. #define __module_param_call(prefix, name, set, get, arg, perm) \
  73. /* Default value instead of permissions? */ \
  74. static int __param_perm_check_##name __attribute__((unused)) = \
  75. BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \
  76. + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \
  77. static const char __param_str_##name[] = prefix #name; \
  78. static struct kernel_param __moduleparam_const __param_##name \
  79. __used \
  80. __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
  81. = { __param_str_##name, perm, set, get, { arg } }
  82. #define module_param_call(name, set, get, arg, perm) \
  83. __module_param_call(MODULE_PARAM_PREFIX, name, set, get, arg, perm)
  84. /* Helper functions: type is byte, short, ushort, int, uint, long,
  85. ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
  86. param_set_XXX and param_check_XXX. */
  87. #define module_param_named(name, value, type, perm) \
  88. param_check_##type(name, &(value)); \
  89. module_param_call(name, param_set_##type, param_get_##type, &value, perm); \
  90. __MODULE_PARM_TYPE(name, #type)
  91. #define module_param(name, type, perm) \
  92. module_param_named(name, name, type, perm)
  93. #ifndef MODULE
  94. /**
  95. * core_param - define a historical core kernel parameter.
  96. * @name: the name of the cmdline and sysfs parameter (often the same as var)
  97. * @var: the variable
  98. * @type: the type (for param_set_##type and param_get_##type)
  99. * @perm: visibility in sysfs
  100. *
  101. * core_param is just like module_param(), but cannot be modular and
  102. * doesn't add a prefix (such as "printk."). This is for compatibility
  103. * with __setup(), and it makes sense as truly core parameters aren't
  104. * tied to the particular file they're in.
  105. */
  106. #define core_param(name, var, type, perm) \
  107. param_check_##type(name, &(var)); \
  108. __module_param_call("", name, param_set_##type, param_get_##type, \
  109. &var, perm)
  110. #endif /* !MODULE */
  111. /* Actually copy string: maxlen param is usually sizeof(string). */
  112. #define module_param_string(name, string, len, perm) \
  113. static const struct kparam_string __param_string_##name \
  114. = { len, string }; \
  115. module_param_call(name, param_set_copystring, param_get_string, \
  116. .str = &__param_string_##name, perm); \
  117. __MODULE_PARM_TYPE(name, "string")
  118. /* Called on module insert or kernel boot */
  119. extern int parse_args(const char *name,
  120. char *args,
  121. struct kernel_param *params,
  122. unsigned num,
  123. int (*unknown)(char *param, char *val));
  124. /* Called by module remove. */
  125. #ifdef CONFIG_SYSFS
  126. extern void destroy_params(const struct kernel_param *params, unsigned num);
  127. #else
  128. static inline void destroy_params(const struct kernel_param *params,
  129. unsigned num)
  130. {
  131. }
  132. #endif /* !CONFIG_SYSFS */
  133. /* All the helper functions */
  134. /* The macros to do compile-time type checking stolen from Jakub
  135. Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
  136. #define __param_check(name, p, type) \
  137. static inline type *__check_##name(void) { return(p); }
  138. extern int param_set_byte(const char *val, struct kernel_param *kp);
  139. extern int param_get_byte(char *buffer, struct kernel_param *kp);
  140. #define param_check_byte(name, p) __param_check(name, p, unsigned char)
  141. extern int param_set_short(const char *val, struct kernel_param *kp);
  142. extern int param_get_short(char *buffer, struct kernel_param *kp);
  143. #define param_check_short(name, p) __param_check(name, p, short)
  144. extern int param_set_ushort(const char *val, struct kernel_param *kp);
  145. extern int param_get_ushort(char *buffer, struct kernel_param *kp);
  146. #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
  147. extern int param_set_int(const char *val, struct kernel_param *kp);
  148. extern int param_get_int(char *buffer, struct kernel_param *kp);
  149. #define param_check_int(name, p) __param_check(name, p, int)
  150. extern int param_set_uint(const char *val, struct kernel_param *kp);
  151. extern int param_get_uint(char *buffer, struct kernel_param *kp);
  152. #define param_check_uint(name, p) __param_check(name, p, unsigned int)
  153. extern int param_set_long(const char *val, struct kernel_param *kp);
  154. extern int param_get_long(char *buffer, struct kernel_param *kp);
  155. #define param_check_long(name, p) __param_check(name, p, long)
  156. extern int param_set_ulong(const char *val, struct kernel_param *kp);
  157. extern int param_get_ulong(char *buffer, struct kernel_param *kp);
  158. #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
  159. extern int param_set_charp(const char *val, struct kernel_param *kp);
  160. extern int param_get_charp(char *buffer, struct kernel_param *kp);
  161. #define param_check_charp(name, p) __param_check(name, p, char *)
  162. extern int param_set_bool(const char *val, struct kernel_param *kp);
  163. extern int param_get_bool(char *buffer, struct kernel_param *kp);
  164. #define param_check_bool(name, p) __param_check(name, p, int)
  165. extern int param_set_invbool(const char *val, struct kernel_param *kp);
  166. extern int param_get_invbool(char *buffer, struct kernel_param *kp);
  167. #define param_check_invbool(name, p) __param_check(name, p, bool)
  168. /* Comma-separated array: *nump is set to number they actually specified. */
  169. #define module_param_array_named(name, array, type, nump, perm) \
  170. static const struct kparam_array __param_arr_##name \
  171. = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
  172. sizeof(array[0]), array }; \
  173. module_param_call(name, param_array_set, param_array_get, \
  174. .arr = &__param_arr_##name, perm); \
  175. __MODULE_PARM_TYPE(name, "array of " #type)
  176. #define module_param_array(name, type, nump, perm) \
  177. module_param_array_named(name, name, type, nump, perm)
  178. extern int param_array_set(const char *val, struct kernel_param *kp);
  179. extern int param_array_get(char *buffer, struct kernel_param *kp);
  180. extern int param_set_copystring(const char *val, struct kernel_param *kp);
  181. extern int param_get_string(char *buffer, struct kernel_param *kp);
  182. /* for exporting parameters in /sys/parameters */
  183. struct module;
  184. #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
  185. extern int module_param_sysfs_setup(struct module *mod,
  186. struct kernel_param *kparam,
  187. unsigned int num_params);
  188. extern void module_param_sysfs_remove(struct module *mod);
  189. #else
  190. static inline int module_param_sysfs_setup(struct module *mod,
  191. struct kernel_param *kparam,
  192. unsigned int num_params)
  193. {
  194. return 0;
  195. }
  196. static inline void module_param_sysfs_remove(struct module *mod)
  197. { }
  198. #endif
  199. #endif /* _LINUX_MODULE_PARAMS_H */